Pump



May 7, 1929. H. J. WEPPLO 1,711,914

' I PUMP Filed Aug, 31, 1927 Patented May 7, 1929.

UNrrED STATES HENRY J.y WEPPLO, 0F MINNEAPOLIS, MINNESOTA.

PUMP.

Application led August 31, 1927. Serial No. 216,648.

This invention relates to new and useful improvements in fiuid pressurepumps and more particularly relates to the construction of the pistonprovided therein.

An object of the invention is to provide an improved piston for a -fluidpressure pump, comprising a leather cup mounted for relative axialmovement upon the piston rod and having air-circulating passagesprovided therein adapted to be opened topermit the entrance of air intothe lower portion of the pump barrel beneath the piston, during itsreturn stroke, and the relative movement of the leather cup upon thepiston rod, automatically causing said air-circulating passages to beclosed, during the pressure stroke of the piston, whereby the pistonwill act as a valve. c

A further object of the invention is toy r eup being adapted to beseated against the disc and having a central opening therein traversedby the clamping member, and means being providedupon the clamping memberfor preventing the leather cup from becoming detached from the pistonrod, but permitting relative axial movement of the piston thereon, and aplurality of air-circulating passages being provided around theperiphery of said clamping member to permit the entrance of air into thelower portion of the pump barrel, beneath the piston, vduring thereturnstroke of the piston, at which time the leather cup will be disengagedVfrom the disc and, when the piston rod is moveddownwardly during itspressure stroke, the disc will be moved into engagement with the upperwall of the leather cup and interrupt the circulation of air through thepiston, whereby the air confined within the pump barrel beneath thepiston may be forced outwardly therefrom through the usual con nection'provided therein.

rlhe particular vobject of the invention therefore Vis to provide animproved piston for a fluid pressure pump, comprising the usual leathercup and supporting discs between vvhich the upper wall ofthe cup ismounted, and the leather cups and retaining dise being secured to thepist-on rod in a man- .ner to permit relative movement of the cup withrespect to the piston rod, so that during the upstroke of the rod, airmay circulate through the piston and, when forced'downwardly during itspressure stroke, the circulation of air through the piston willautomatically be interrupted.

Other objects of the invention will appear from the followingdescription and aecompanying drawings and will be pointed outv .in theannexed claims.

various changes may be made within the scope of the claims which follow.n

ln the accompanying drawings forming part of this specification:

Figure 1 is an elevational view of a conventional form of pump,partially broken away to show the invention applied thereto;

Figure 2 is an enlarged detailed sectional view illustrating the generalconstruction of the improved piston and showing the parts positioned topermit the circulation of air through the piston during its return orupwa-rd stroke; i

Figure 3 is a view similar to Figure 2, showing the position of theparts during the pressure stroke;

Figure 4 is a sectional plan view on the line lf-4 of Figure 2, showingthe air-circulating passages provided around the clamping member securedto the lower end of the piston rod; and

' Figure 5 is a detailed sectional view showing a modified form.

In the lselected embodiment of the yinvention herel shown, for purposesofvdisclosure, there is illustrated a conventional liuid pressure pump,comprising the usual barrel 2, suitably mounted in a base 3 having anout let 4L provided therein to which a flexible conneetion may beconnected, as shown. A cap 6 is suitably secured to the upper end of thebarrel and has a central aperture therein traversed by the usual pistonrod 7, having a hand grip 8, as shown.

The particular feature of this invention resides inthe generalconstruction of the piston, provided at the lower end of the piston rod7; This piston is Aconstructed in such a manner as to permit thecirculation of air therethrough from the upper portion of the CII pumpbarrel into the lower portion beneath the piston, during the returnstroke of the latter', and without the use of additional valves, asiscustomary in devices of this kind.

The improved piston here shown comprises a disc 9 adapted to be seatedagainst a nut 10 received in threaded engagement with the lower end 11of the piston rod, as particularly shown in Figure 2.

A suitable leather cup 12, such as are commonly used in devices of thiskind, is mounted beneath the fixed disc 9 and has a central aperture 13adapted to be traversed by .a clamping member or nut 14, received inthreaded engagement with the terminal of the rod and clampingly engagedwith the disc 9 to secure it to the rod against the nut 19. The clampingmember 14 is preferably constructed or turned from a square rod as shownin Figure 4, so that projections 15 are provided thereon which overhangthe upper horizontal wall 16 of the packing 12, as shown in Figures 1and 4. A retaining disc 17 is mounted within the leather cup 12 and alsohas a central aperture 18 adapted to receive the reduced or turnedportion of the clamping member 14, as shown.

A plurality of flat faces 19 are provided on the turned portion of theclamping member 14, or that portion thereofl which passes through theretaining disc 17 and the upper wall 16 of the packing. These flat facesprovide air-circulating passages, through which air may circulatethrough the piston and into the lower portion of the pump barrel, duringthe upstroke of the piston, as shown in Figure 2. The upper faces 2O ofthe projections 15 of the clamping` member are spaced from the upperface of the clamping member or the fixed disc 9, a distance suiiicientto permit relative axial movement of the packing and the retaining disc17 upon the piston rod, during the reciprocal movement of the rod 7 andshown in Figures 2 and Thus, when the piston rod'is moved upwardly, asindicated by the arrow in Figure 2, the retaining disc 17 will engagethe upper' faces 2O of the projections 15, thereby providing a spacebetween the lower face of the disc 9 and the upper face of the wall 16of the packing, and permitting vair to flow from the upper portion ofthe pump barrel between the fixed disc 9 and the upper wall 16 of thepacking, and thro ugh the air-circulating passages, provided. around theturned portion of the clamping member 14, and into the lower porf tionof the barrel, as indicated by the arrows in Figure 2. Conversely, whenthe piston rod is forced downwardly during its pressure stroke, thefixed disc 9 will engage the upper wall 16 of the packing, therebyautomatically interrupting the circulation of air through the piston,with the result that the air confined within the pump barrel beneath thepiston will be forced outwardly therefrom through the connection 5. Bythus loosely mounting the packing upon the' piston rod 7, and in theparticular manner above described, the piston itself will function as avalve, permitting to circulate therethrough during its up-stroke, andinterruptthe passage of air therethrough upon its down-stroke. Noadditional valves are therefore required, with the result that thepiston may be manufactured at a greatly reduced cost, as compared withdevices of this kind now in use. It has been found that byY Abecause ofthe fact that very little effort is required to operate the piston rodduring its return stroke, the air-circulating passages through thepiston being of ample size to permit freedom of air-circulationtherethrough without offering any material resistanceV to the movementof the piston rod.

Figure 5 illustrates a modified form wherein the clamping member 14,provided beneath the fixed disc 9, is provided with a cylindricalportion 21 adapted to traverse the openings provided in the disc 22 andthe upper wall 16 of the leather cup 12. In this instance, the disc 22is provided with a plurality of slots or recesses 23 communicating withthe bore or aperture therein and extending outwardly therefrom beyondthe head 24 of the clamping member, in this case shown to be hexagonal.The slots 23 provide air-circulating passages through the piston in amanner similar to the flat faces 19 provided in the clamping member 14,lshown and describedfin the previous figures.

I claim as my invention: f

l. In a pump, the combination of a barrel having a piston rod mountedfor reciprocal movement thereinand having ay shoulder adjacent its lowerend, a disc seated against said shoulder, a leather cup having a centralopening therein adapted to be seated against said disc, a nut receivedin threaded engagement with the lower end of the rod and having areduced portion passing through the aperture in said packing andclampingly engaged with said disc, said nut having ahead adapted toretain said packing thereon and spacedfrom the disc sufficiently topermit axial movement of the leather cup with respect to the piston rod,when the latter is operated, and air-circulating-passages between thereduced portion of said nut and the walls of the aperture in said cup topermit the flow of air through the piston when the rod is drawnupwardly.

2. In a pump, the combination of a lbarrel having a piston rod mountedfor reciprocal movement therein and having its lower end threaded, a nutsecured to the lower threaded end of said rod, a disc seated againstsaid nut, a leather cup adapted to -be seated against said disc andhaving a central opening therein, a second disc mounted within said cupand also having a central opening therein', a member received inthreaded engagement with the threaded termina-l of said rod andclampingly engaged with said irstv mentioned disc, said member passingthrough the apertures in said packing and said second mentioned disc andhaving means thereon adapted to engageathe disc mounted within the cup,to prevent the latter from becoming detached from the piston rod, saidmeans permitting axial movement of said leather cup with respect to thepiston rod, and said member also having a plurality of flat facesproviding air-circulating passages between it and the walls of theapertures in the packing and the disc mounted therein whereby, duringthe suction stroke of the piston rod, air willcireulate between the Xeddisc and the leather cup and through the air passages provided aroundsaid memrhaving a piston rod therein provided with a piston comprisingan abutment washer secured to the lower portion of the piston rod andspaced from the adjacent terminal thereof, a leather cup adapted to beseated against said washer and having a central aperture adapted toreceive the terminal oit' said piston rod, a member secured to saidterminal, traversing said aperture and having one end seated againstsaid washer, air circulation passages between the walls of said apertureand said member, and means on said member Yfor retaining the leather cupon said piston rod and permitting relative axial movement of v the cupthereon, whereby the cupk will act as a valve to permit the passage ofair through the piston, when the latter is operated in one direction.

In witness whereof, I have hereunto set my hand this 29th day of August,1927.

. HENRY J. VVEPPLO.

